trans shifts too quickly 1985 auto

I have an electrical problem which affects my transmission shifting. I have a digital dash cluster problem which causes my battery to drain and I bought the car that way 2 months ago. When I put the 5 amp LCD fuse in the fuseblock, the automatic shifts thru all the gears into automatic torque converter lockup in a few seconds into highest gear at about 25mph. When I remove the fuse it shifts normally and this sequence is 100 % repeatable. It feels like an 80's checy I used to have that the "passing gear" kickdown lever had fallen off when the fuse is in. Any ideas ?

IF you have the factory stock/original engine/transmission setup...the shift points should be contolled by the TV cable and the tranny governor. The converter clutch lock up is controlled by the ECM which does use the instrument cluster for a vehicle speed signal...the ECM also uses the transmission as input for when it has shifted to 4th gear...before the ECM engages converter lock up. Couple of questions... when the IP fuse is installed does the speedo work and if so...does it appear to be accurate ?? BTW... one more question...with fuse installed and shifter in 3rd gear (not drive)..does it still shift too quickly and  go into converter clutch lockup ?

|UPDATED|9/16/2012 10:01:27 AM (AZT)|/UPDATED|

The speedo does not work yet - looking for bad ground.

Ya...the fuse should have no effect on when/how the trans shifts at all. It's a completely hydraulic trans...no electronics, other than a solenoid for controlling the Lock up converter, and the pressure switch already mentioned. The trans operates/shifts totally off of the TV cable, attached to the throttle body, and the governor, on the driver side rear of the trans. You can unplug the connector on the trans and it will still shift fine, it just will not have lock up, unless it has been modified to eliminate the electrics....and a lot of them have been by now.

|UPDATED|9/19/2012 10:29:54 AM (AZT)|/UPDATED|